Rotary jar



J. S/BECK 1 8 now/m JAR Filed Oct." 6. 1931 2 Sheets-Sheet 2 Inventor Oct, 25,1932.

Patented Oct. 25, 1932 JULIUS S. BECK, 015 LOS ANGELES, CALIFORNIA ROTARY JAB.

Application filed October 6,

My invention relates to rotary jars, and has particular .reference to a device for jarring a drill string such as is employed for earth boring, for oil wells, and the like.

In the art of earth boring, it frequently occurs that the bit attached to the end of the drill string becomes so caught in the strata through which the bore is passing that it is impossible to further rotate the jar and it is 10 necessary to apply some force which will free the bit. Prior devices have comprised interconnected members which, upon a reverse rotation of the drill string, will cause a hammer blow to be given to the drill string to jar the bit free from the material in which it is caught.

With the introduction of deep Well drilling by the rotary method, it has been found desirable to jar the bit by means of placing an upward tension upon the drill string rather than to'depend upon the reverse rotation of the drill string, since the extreme length of the drill string normally permits several complete rotational twistings of the drill strings between the point of application of power and the bit so that it would be necessary to first permit the torsional strain to be taken out of the drill string and then further reverse rotation given to the spring before the jarring would take place; Moreover, the opportunity for the drill string to separate at one or more of its joints during the reverse movement would begreat and these conditions are avoided when the jar is operated by a direct upward pull on the drill string.

Moreover, it is desirable that the jar should operate at different amounts of force applied to the drill string, since such jar could be interposed in the drill string at any point along the string, and the normal tension resulting from the weight of the string below the jar could be accurately compensated for by adjusting the strain for operating the ar.'

45 It is, therefore, an object of my invention to provide a jar for use in rotary drilling in which the jar will be actuated upon the exertion of a predetermined upward force upon the drill string and which may be readily reset to permit repeated jarring operations.

Another object of my invention is to projar.

1931. Serial No. 567,166.

vide a rotary jar as described in the preceding paragraph in which the length of the stroke permitted in the jarring operation may be readily adjusted.

Another object of my invention is to provide a rotary jar for drill strings in which the jarring members are normally locked together to prevent relative rotational movement thereof to thus prevent possible disconnection of the jar and bit.

Other objects and advantages will be apparent from a study of the following specifications, read in connection with the accompanying drawings, in which i Fig. 1 is an elevational view, shown partly in section, of a jar constructed in accordance with my invention;

Fig. 2 is a detail, sectional view of the jar illustrated in Fig. 1, taken along line 11-11 of Fig. 1, and illustrating the lockingdevice for the bit connection; 1

Fig. 3 is an enlarged view, similar to Fig.

1, showing the arring members in their relative positions after operation of the jar;

Fig. 4 is an enlarged vlew, slmilar to Fig. 1,

illustrating the relative positions of the jarring members during the resetting operation ofthe jar;and

Fig. 5 is an enlarged view, similar to Fig.

1, illustrating the jarring members when adjuste'd to shorten the length of stroke of the Referring to the drawings, I have illustrated in Fig. 1, a jarring device which comprises an outer shell 1 provided with a longitudinally extending bore 2 through which passes a mandrel 3, the bore and the mandrel preferably having complementary geometri cal shapes permitting relative longitudinal movement of the shell and mandrel but preventing relative rotational movement of these two members. Thus the mandrel 3 is mounted for telescopic movement within the shell 1.

The mandrel 3 is illustrated as having its extreme lower end 4 threaded to engage the .95 upper end of a lower sub 5 which terminates in a threaded pin 6 to receive the threaded end of a bit or an additional length of drill string which may be attached thereto.

The upper end of the shell 1 is illustrated piece of material as having a threaded bore 7 therein, adapted to receive the threaded end ofthe upper portion of a drill string, (not shown), so that the jar may be interposed between any two sections of drill string, or between the lower section of drill string and the bit.

The mandrel 3 is illustrated as having an enlarged portion 8 near its upper end, this portion being preferably of circular cross section and terminating in a lower shoulder 9 adapted to engage an inwardly extendin shoulder 10 formed upon the interior of the shell. The shoulders 9 and 10 constitute in effect abutting shoulders which will receive the impact between the shell 1 and the mandrel 3 when the jarring operation takes place.

A nipple 11 is illustrated as being connected to the upper end of the mandrel 3 and the nipple is in turn connected at its upper end to the lower end of a section of tubing 12, which may constitute the conduit for suitable lubricating fluids or flushing fluids ordinarily passed downwardly through the interior of the drill string during the drilling operation.

The shell 1 and the mandrel 3 are normally interconnected to hold these members in their telescoped or contracted position, as illustrated in Fig. 1, by means of a primary sleeve 13 surrounding the nipple 11 and rigidly connected therewith as by means of an elongated thread 14 upon the nipple 11 engaging the interiorally threaded end 15 of the primary sleeve 13.

The primary sleeve 13 is illustrated as constituting a tubular section of resilient material having upon its outer periphery a radially extending portion or shoulder 16 extending beyond the normal outer periphery of the sleeve'13. The sleeve 13 is further provided with an enlarged interior bore 17 so that the maJor portion of the interior of the sleeve 13 is spaced slightly away from I the outer walls of the nipple 11. Hence pres sure exerted upon the shoulder 16 will tend to contract the sleeve 13 toward the nipple 11. If desired, the contracting effect may be assisted'by providing a .plurality of longitudinal cuts or serrations 18 at spaced intervals around the periphery of the sleeve 13, thus eflectively dividing the sleeve 13 into a plurality of spring sections, each of which bears a portion of the shoulder 16.

A secondary or finger sleeve 19 is illustrated as surrounding the nipple 11 and its associated primary sleeve 13, the secondary or finger sleeve constituting a cylindrical having a plurality of Iongitudinal cuts or serrations extending a considerable distance along its length to thus provlde in effect a plurality of longitudinally extending spring fingers 20 connected at their upper ends to an annular ring or collar portion 21. Each of the fingers 20 is illustrated as being slightly enlarged at its lower end 22 to provide an inwardly extending gripping surface to engage the surface of the shoulder 16 of the primary sleeve 13.

The secondary or finger sleeve 19 is illustrated as'being connected at its upper or collar end to a nipple 23, the upper end of which is provided with an elongated threaded portion 24 to be engaged by a plurality of llnks or lock-washers 25 and 26. The lower lochnut 25 is illustrated as constituting a radlg ally extending shoulder adapted to engage an inwardly extending shoulder 27 formed upon the interior of the shell 1 so that the finger sleeve 19 may be normally maintained against downward movement relative to the shell 1 by the interengagement of the shoulder 27 and the locknut 25, while the finger sleeve 19 may be moved upward relative to the shell 1,-but may normally be urged to.

its lower position as by means of a helical spring 28 engaging the shell 1 and the upper locknut 26, respectively.

From an inspection of the construction thus far described, it will be observed that the shell 1 and the mandrel 3 are normally interconnected with each other by the engagement of the inwardly directed fingers 20 engaging the outwardly extending shoulder 16 of the sleeve 13 though upon the exertion upon the shell 1 of a predeterm ned upward force, the shell and the spring fingers will be lifted to exert a radially directed pressure against the shoulder 16 and the fingers 20 will be drawn past each other.

However, as stated above, it may be desirable to increase or decrease the force exerted between the fingers 20 and the shoulder 16, resisting the disconnection of these two members, and for this reason I have illustrated the spring fingers 20 as being sup ported by the shell through the agency of the elongated thread 24 and the locknut 25 so that the locknut may be adjusted upwardly or downwardly upon its thread to permit the fingers 20 to either ascend or descend relative to the shell 1. It will also beobserved that the shell 1 is provided with an interior bushing 29, substantially wedge-shaped in cross section with the narrow portion of the wedge directed upwardly to engage the outside of the sleeve formed by the spring fingers 20 sothat when the spring fingers 20 are moved downwardly relative to the shell,

the wedge shaped cross section of the bushing 29 will cause the spring fingers to be pressed inwardly toward the primary sleeve 13 so that the extreme ends 22 of the fingers are held in close engagement with the sleeve 13 and a greater force will be required to draw the fingers 20 past the shoulders 16. In other words, the amount of radial movement of the bushing 29 thus requiring that the shoulders 16 shall be depressed to a greater extent before the fingers 20 will be released permitted the fingers 20 is restricted by means from the shoulders upon a relative movement between the fingers and the shoulders. By adjusting the locknut 25 to any desired position, any desired amount of force may trated as having ascended in relation to the mandrel 3 to such an extent that the abutting shoulders 9 and 10 are in contact with each other, while the spring fingers have been drawn upwardly past the shoulders 16 on the primary-sleeve 13.

It will be observed that on the upward movement, the relative position of the spring fingers 20 and the bushing 29 is unchanged,

the fingers 20 will be in their same radial position as when the jar is in-its contracted position prior to the jarr ng action.

It will be understood by those skilled in the art that the upward strain placed upon the drill string necessary to operate the arwill cause a stretching of the drill str1ng which in an ordinary depth of well will constitute a stretch amounting to at least several feet so that when the spring fingers 20 disengage the shoulder 16, the elasticity of the drill string tending to take up the stretch willbe such that a rapid upward movement is given the shell and'the abutting shoulders 9 and 10 will be brought together with forcible impact.

If the first jarring operation does not dislodge the bit, the drill string may be lowered to reseat the jar for a second jarring operation. The reseating operation consists .merely in the lowering ofathe drill string which consequently lowers the shell 1 relative to the mandrel 3, which remains stationary. However, as the shell descends, the spring fingers 20 will be carried with it until the ends 22 of the fingers engage the upper side of the shoulder 16 on the primary sleeve 13. Further downward movement of the shell may occur, but the spring fingers 20 will remain in the position illustrated in Fig. 4, abutting the upper side of the shoulder 16. However, the bushing 29 will move downwardly with the shell, thus permitting outward flexing of the spring fingers 20 without the restraint normally imposed by the bushing. Therefore the force which is exerted by the'spring 28, tending to push the spring fingers downwardly, will be sufficient to pass the fingers over the shoulders 16 and thus move the spring fingers to their normal position, as illustrated in Fig. 1.

' By mounting the springs movable relative to the shell, lowering of the drill string after the jarring operation, will cause the shell and mandrel to move back to their original positions by gravity, the spring fingers engaging the split sleeve and being moved upwardly away from the wedge 29 so that the spring fingers may readily pass the shoulders 16 on the sleeve after which the spring 28 will press the spring fingers back into engagement with the wedge to position them upon. the lower side of the shoulder 16. All of the above operations will occur without the necessity of applying any pressure to the parts other than the normal weight of the drill string above the jar. Moreover, the employment of the spring 28 permits the spring fingers 20 to be normally arranged to exert considerable force upon the shoulder 16, this force being overcome by the compression of the spring 28 as the jar moves back to its normal or contracted position.

From an inspection of Figs. 1, 2 and 3, it will be observed that the amount of movement permitted between the mandrel 3 and the shell 1 is of considerable extent to insure the production of a substantial impact.

, However, it may be desirable, when drilling in substantially soft strata or when the bore is not very deep, to permit the jarring operation to occur without the expenditure of the great amount of forces which may be required at greater depth or in harder strata. For this reason I have arranged for the reduction of the normal stroke of the jar to permit the stroke to be adjusted to the most desirable condition.

The adjustment of the jar for length of stroke may be readily accomplished through the interconnection of the primary sleeve 13 with the mandrel 3 to permit thelongitudinal aldjqlistment of the sleeve relative to the man- Referring, particularly, to Fig. 5, it will be observed that the threaded engagement between the nipple 14 and the sleeve 13 is such that the sleeve 13 may be screwed upwardly along the nipple through a considerable distance. The sleeve 13 is illustrated as being heldin whatever position is desired by means of a link or jamb nut 30 which is also threaded upon the nipple 14 and brought into locking engagement with the lower end of the sleeve 13. If the sleeve 13 is screwed upwardly upon the nipple 14, it follows that the interconnection of the mandrel and shell (b the spring fingers 20 and the shoulders 16 will be at'a greater distance from the mandrel and shoulder 9 than when the sleeve be observed that the interconnection between the lower end of the mandrel 3 and the lower sub 5 is by means of a screw-thread engagement. Hence any reverse rotation which may be given to the mandrel will tend to loosen this threaded engagement. However, normally, any rotary force which is exerted upon the lower sub 5 will be transmitted through the shell 1, preferably by a direct connection between the sleeve and the lower sub, as by means of the formation of a plurality of longitudinal slots 31 arranged at spaced intervals around the periphery of the shell 1 to engage longitudinally extending fingers 32 secured to the lower sub 5. Thus, in addition to the hexagonal, or similar geometrical shape, of the mandrel 3, relative to the shell 1., the torsion will be distributed to the outer portion of the shell 1. However, when the shell 1 is drawn upwardly to operate the jar, the fingers 32 will disengage the slots 31 and hence any torsional strains which may be in the drill string at that time will be exerted entirely through the interacting shapes of the mandrel and the shell.

Thus, if at the time the jarring operation occurs, there is a torsional strain in the drill string, the release of the bit under the impact of the jar wouldpermit the drill to be rotated by the torsional force in the drill string. This force might be so great as to unscrew the lower sub 5 from the end 4 of the mandrel 3. On the other hand the torsional strain might be in a reverse direction so that when the fingers 32 disengage the slots 31 the entire torsional strain would be taken by the threaded engagement between the lower sub 5 and the end of the mandrel 3 tending to unscrew these parts.

I prefer to provide a positive locking means for preventing thepossibility of unscrewing the mandrel and the lower sub 5, this means comprising a collar 33 having a circular outer periphery conforming with the outer periphery of the shell 1 and having an inner periphery of a selective shape to fit the outer periphery of the mandrel with which it is engaged. For example, if the mandrel is hexagonal in shape, the inner periphery of the ring or washer 33 should be hexagonal. Thus prior to the assembly of the mandrel and the lower sub '5, this ring or washer 33 can he slipped upon the lower end of the mandrel and then, after the lower sub is screwed into tight engagement with the mandrel, the washer 33 can be drawn downwardly toward the sub and fixed in place as by means of a plurality of set screws 34. I

It will be observed that the upper end of the lower sub 5 is provided with a plurality of longitudinal slots 35 substantially identical with the slots 31 in the lower end of the sleeve. The slots 35 may be engaged by a plurality of downwardly extending longi- .will be accomplished. a

It will be observed that the mandrel 3 is provided with a central longitudinal bore 37 through which flushing or lubricating fluids, which pass down through the tubing 12, may pass to the bit secured to the lower end of the lower sub 5 so that such fluids may readily pass through the jar during the normal drilling operations. However, when the drill becomes stuck and the jar is actuated to break the drill loose, it is desirable that a portion of the fluids be permitted to escape outside of the shell 1 to assist in loosening the dbris which is causing the sticking of the drill. For this purpose it may be desirable to provide a radially extending bore 38 through the mandrel 3 communicating with the central bore 37. However, the location of the radial bore 38 should'be such that when the jar is in its normal position, such as shown in Fig. 1, the passage through the bore 38 should be closed to prevent escape of the flushing fluid.

I have illustrated the two main members of the jar as having packing 39 interposed therebetween near the lower end of the struc ture, while a similar paclnng 40 may be provided nearest the upper end of the device to insure against undue escape of the flushing fluids to the space between the shell and the mandrel with its assembled structure. Hence the radial bore 38 should be so located that when the mandrel and shell are in their retracted position, as shown in Fig. 1, the outer end of the bore 38 should be engaged by the packing 39 and this will constitute a cutoff for the passage of fluids therethrough. However, when the shell and mandrel are in their extended position, after the jarring operation, the bore 38 will be in a position free of the packing 39 and below the same, so that the fluid in the central bore 37 may readily pass radially outward.

While I have illustrated and described the preferred embodiment of my invention, I

do not desire to be limited to any of the derected toward said other member, a second sleeve carried by said other member and hav ing means formed thereon for engaging said shoulder to hold said members in contracted position but releasable by the exertion of such longitudinal strain as will cause flexing of said resilient sleeve.

2. A jar for use in rotary drilling comprising two members telescopically assembled one within the other for relative longitudinal movement from a normal contracted position to an extended position, striking abutments formed on said members interengageable when said members are in extended position, a resilient sleeve carried by one of said members arranged to flex radially toward that member, a shoulder formed on said sleeve directed toward said other member, a second sleeve carried by said other member and having means formed thereon for engaging said resilient sleeve below said shoulder means and filling the radial space between said resilient sleeve and said other member to hold said members in contracted position but releasable by the exertion of longitudinal strain between said members suflicient to flex said resilient sleeve.

3. A jar for use in rotary drilling comprising two members telescopically assembled one within the other for relative longitudinal movement from a normal contracted position to an extended position, striking abutments formed on said member interengageable when said members are in extended position, a resilient sleeve carried by one of said members arranged to flex radially toward that member, a shoulder formed on said sleeve directed towardsaid other member, a second sleeve carried by said other-member and having means formed thereon for engaging said shoulder to hold said members in contracted position.

but releasable by the exertion of such longitudinal strain as will cause flexing of said resilient sleeve, said other member having a tapered surface directed downwardly and toward said resilient sleeve, and means for adjusting said second named sleeve longitudinally relative to said tapered surface to decrease or increase the radial space between said shoulder-engaging means and said shoulder.

4. A jar for use in rotary drilling comprising two members telescopically assembled, one within the other, for relative longitudinal movement from a contracted position to an extended position, striking abutments formed on said members interengageable when said members are in extended position, an elongated sleeve secured to one of said members and having a portion of its sleeves adjacent that member out of contact with that member to permit radial flexing of said resilient sleeve relative to that member, a'radially directed shoulder formed upon the surface of said resilientsleeve directed toward said other member, and means carried by said other member for engaging said shoulder to 5. A jar for use in rotary drilling bom prising two members telescopicallyassembled one within the other for relative longitudinal movement from a contracted position to an extended position, striking abutments formed on said members interengageable when said members are in extended position, an elongated resilient sleeve secured to said inner member and having a portion of its surface adjacent said inner member and spaced from said inner member to permit radial flexing of said sleeve,a shoulder formed upon the outer surface of said sleeve, a second sleeve carried by said outer member and having a plurality of longitudinally extending fingers formed thereon to engage below said shoulder to normally hold said inner and outer members in contracted position, means formed on said member to provide a downwardly and inwardly directed surface thereon for engaging said fingers to press said fingers toward said shoulder, and means for variably adjusting said fingers relative to said tapered surface for radially adjusting the positions of said fingers and said shoulder.

6. A jar for use in rotary drilling comprising two members telescopically assembled one within the other for relative longitudinal movement from a contracted position to an extended position, striking abutments formed on said members interengageable when said members are in extended position, an elongated resilient sleeve secured to said inner member and having. a portion of its surface adjacent said inner member and spaced from said inner member to permit radial flexing of said sleeve, a shoulder formed upon the outer surface of said sleeve, a second sleeve surrounding said first sleeve and having formed thereon a plurality of longitudinally extending fingers engaging said first sleeve and below said shoulder, means mounting said second sleeve within said outer member, adjustable abutting means formed upon said outer member and said second sleeve for limiting the downward movement of said sleeve relative to said outer member, and spring means normally urging said second sleeve into abutting relation with said outer member.

7. In a well drilling tool the combination of a mandrel having means at its lower end for connection to a tool to be jarred, a tubular member slidable on said mandrel and having means for connection toa drill string, said tubular member having a wedging surface, a resilient sleeve connected to the mandrel and having a cam surface, a wedging means having a plurality of fingers encircling the sleeve and having a small slipping action in regard to the tubular member and suspended thereby, said fingers being adapted to engage between the cam surface on the sleeve and the wedging surface of the tubular member, and to resist an upward pull on said tubular member until suflicient stress is developed to deflect the sleeve inwardly to release the said fingers, and means interacting between the mandrel and the tubular member to exert a jarring blow on the upward movement of the tubular member relative to the mandrel.

8. In a well drilling tool the combination of a mandrel having means at its lower end for connection to a tool to be jarred, an upper tubular member including a shell, said shell structure having an internal wedging surface, a split sleeve connected to the mandrel, a supporting structure having an adjustable hearing on the said shell, said structure having depending split fingers with encircling finger tips to engage between the wedging surface on the shell and the cam surface on the split sleeve, the said fingers resisting an upward pull on the tubular member until the sleeve is deflected inwardly, and means interacting between the shell and the mandrel to exert a jarring blow in the upward movement of the tubular member on the mandrel.

9. A jar for use in rotary drilling, comprising an outer shell member having means for connecting the same to a drill string, an inner mandrel member telescopically assembled within said outer member, a lower sub secured to said mandrel for connecting a shell to said mandrel, interengaging means on said shell and mandrel for preventing relative rotation of said members in either extended or contracted a position, striking abutments formed on said members interengageable when said members are in extended position, means yieldingly holding said members in contracted position but releasable by the ex ertion of a predetermined longitudinal strain between said members, a plurality of longitudinal slots formed in the lower end of said shell, a plurality of longitudinal slots formed in the upper end of said lower sub, and a lock washer secured to said mandrel and having longitudinal fingers thereon engaging said longitudinal slots in said shell and said sub to further prevent the relative rotation between said shell and said mandrel.

10. A jar for use in rotary drilling, comprislng an outer shell member having means for connecting the same to a drill string, an inner mandrel member telescopically assembled within said outer member, a lower sub secured to said mandrel for connecting a shell to said mandrel, interengaging means on said shell and mandrel for preventing relative when said members are in extended position, means yieldingly holding said members in contracted position but releasable by the exertion of a predetermined longitudinal strain between said members, a plurality of longitudinally extending slots formed in the upper end of said lower sub, and a lock washer secured to said mandrel and having longitudinally extending fingers engageable with said slots in said lower sub and preventing relative rotation between said lower sub and said mandrel.

11. A jar for use in rotary drilling comprising a shell member, a mandrel member telescopically assembled within said shell member, interengaging means for preventing relative rotation of said shell and mandrel members, striking abutments formed on said shell and mandrel members interengageable when said shell and mandrel are in extended position, means on said mandrel member forming a radial shoulder directed toward said shell, means on said shell engaging said shoulder to normally hold said shell and mandrel in contracted position but releasable by the exertion of a predetermined longitudinal strain between said shell and mandrel members, and means for adjusting said shoulder forming means relative to said striking abutments to variably adjust the length of movement permitted said shell and mandrel members between extended and contracted positions.

Signed at Los Angeles, 9th day of September, 1931.

JULIUS S. BECK.

California, this rotation of said members in either extended or contracted position, striking abutments 

